1. Field of the Invention
The invention relates to an apparatus and method for reestablishing previously established settings on the controls of an audio mixer or mixing console.
2. Description of Background Information
Audio mixers used in modern recording studios are provided with a number of different input channels for receiving audio signals. The function of the audio mixer is to vary the strength of the signals from the various input channels for receiving audio signals so as to produce a desired "mix" of sound as the final product. To this end, audio mixers include a plurality of mixing faders which determine the strength or amplitude of each signal from each input channel. In addition, audio mixers include channel mute controls for selectively turning each selected input channel on or off, as well as a panning controls for determining the left to right stereo positioning of the final output.
At each recording session, the audio engineer determines the desired "mix" for the music to be recorded by manipulating the settings on the various controls of the audio mixer. When the desired "mix" has been achieved, the recording session begins. It is common in recording live music, that more than one recording session will be required for recording the music of a particular group. It is also common that between these recording sessions, the recording studio will record other groups with the same audio mixer. As a result, the settings on the various controls of the audio mixer will be changed between the first and second recording session of a particular musical group. Thus, it is necessary for the audio engineer to manually record the settings on the controls of the audio mixer after the first session so that the settings can be reproduced during the second session. However, manually recording all of the settings on the audio console is time consuming and imprecise. Thus, there is a need for some type of automated system for reestablishing previously established settings on the controls of the audio mixer.
Several automation systems have previously been developed, but each of the systems have serious disadvantages. One system uses a voltage controlled amplifier as the gain element, instead of a potentiometer or pad which is normally used as the mixing fader. This type of system is manufactured by: Audio Machinery, Gelbart, MCI, INC., MCI Division of Sony Corporation, Sound Workshop, Valley People, Allison Research, and Solid State Logic of England. The mixing fader which this type of system automatically manipulates comprises a voltage divider. The physical position of the voltage divider determines the voltage output of the mixing fader. This output of the mixing fader is fed to the input of a voltage controlled amplifiers which comprises one component of the automated system. This DC control voltage is then digitized and recorded by the automated system. At a later time the digitized recording of the DC voltage gain can be read and the same DC control voltage can be generated by a digital to analog converter. The output of the digital to analog converter is connected to the control input of the voltage controlled amplifier which, therefore, in effect controls the gain or volume level out of that particular " mixing fader". As the recorded data changes over time, the DC control voltage changes and therefore the gain or volume level of the signal produced by the voltage control amplifier and the mixing fader changes.
A second type of automation system for reestablishing previously established settings on the controls of an audio mixer is manufactured by GML-George Massenburg Labs and by Rupert Neve of England. This type of automated system comprises a motorized mixing fader with a tachometer. The tachometer measures the physical position of the mixing fader. Also provided is a means for recording the position of the mixing fader by recording the setting on the tachometer at a particular time. At a later time the recording can be read and this information is fed to a motor which adjusts the position of the potentiometer of the mixing fader until it is in its previous position. As the recorded data changes the motor will make any adjustments necessary to change the position of mixing fader.
A third type of automated system, is manufactured by Solid State Logic of England, includes a rotary control comprising an additional gain or potentiometer on the same shaft as the mixing fader. This additional potentiometer comprises a voltage divider so as to provide on its wiper a voltage varying with the position of the control. This automatic mechanism also includes a means for digitizing and recording this voltage. At a later time this recording of the digitized voltage can be reproduced and compared with the current voltage from the same gang of the same potentiometer. The operator then manipulates this control of the mixing fader until the difference between the old setting and the current setting are 0.
All of these automated systems require a controllable gain device which comprises either a voltage controlled amplifier or a motorized mixing fader. Both of these types of devices are expensive and cumbersome. Furthermore, the automatic system comprising the rotary control requires additional hardware in the form of multi-ganged potentiometers, as well as a very large data acquisition or scanning system, and wiring which must be built in or installed for this system to operate.
Thus, there is a need for an automated system for reestablishing previously established settings on the controls of an audio mixer that is both inexpensive and not cumbersome to install.